Tire technology has rapidly evolved over the last few decades, and this is especially true in racing. NASCAR tires have changed every bit as much over the years as the Sprint Cup cars. Today, they remain one of the critical pieces that will determine victory or defeat.
Since 1997, Goodyear has been the sole provider of tires for all NASCAR race series. The Goodyear Race Eagle is the tire getting the job done, familiar to race fans due to the distinctive thick yellow lettering. Goodyear tests the tires extensively to make sure they can survive 200 miles per hour, for several dozen laps. Running that kind of speed means 3,000 tire revolutions per minute, which can build up a ton of heat. Tire changers report temperatures around 200 degrees Fahrenheit when they have their hands in there.
The Racing Eagle needs to be high tech to take this abuse, and they are much more than just round rubber donuts filled with air. Each tire has a radio frequency identification tag embedded. Basically, this chip tells date of manufacture, batch number, exact size, and so on. Due to production variables, no two tires are exactly alike, but the RFID chips let teams find tires that are very evenly matched. Two other features that differ from road tires are the inner liner and nitrogen. The “lifeguard” inner liner prevents dangerous blowouts by providing a tire within a tire. The race car can drive on this inner liner for a short time, preventing serious accidents. A nitrogen fill is another safety feature, as the gas is inert, so it will not react to the high temperatures the way air would.
Racing Eagles are a racing slick, which looks like at first glance like a fat bald tire. Street tires have grooves for channeling water and debris, while still gripping the road. Race cars need maximum grip, so the entire surface becomes the contact patch gripping the track. While it works great on a dry track, the lack of tread groves mean the tires are terrible in the rain. This is the reason NASCAR has rain delays. The cars can handle rain, but the tires can’t.
NASCAR runs a very plain, “old school” steel wheel. They do this for strength, not aesthetics. They are usually from AERO or Bassett Racing, and measure 15 inches diameter, and 9.5 or 10 inches wide. While anyone can buy these wheels and fit them to a road car, the wheels are not DOT approved. On this wheel, the Racing Eagle is mounted, sized 28/10-15.
Race-spec Eagles are not cheap, running over $400 each. In 2014, teams spent an average of $20,000 for tires at each race. That’s a lot of tires. NASCAR recently partnered with Liberty Tire Recycling, to solve the 120,000 annual tire problem. The tires will be shredded for rubber garden mulch, or melted and added to asphalt for racetracks and parking lots. Any tires that don’t end up recycled will probably find their way to eBay, where they sell for about half the price of new. Much more if autographed.